/******************************************************************************
 * Spine Runtimes License Agreement
 * Last updated January 1, 2020. Replaces all prior versions.
 *
 * Copyright (c) 2013-2020, Esoteric Software LLC
 *
 * Integration of the Spine Runtimes into software or otherwise creating
 * derivative works of the Spine Runtimes is permitted under the terms and
 * conditions of Section 2 of the Spine Editor License Agreement:
 * http://esotericsoftware.com/spine-editor-license
 *
 * Otherwise, it is permitted to integrate the Spine Runtimes into software
 * or otherwise create derivative works of the Spine Runtimes (collectively,
 * "Products"), provided that each user of the Products must obtain their own
 * Spine Editor license and redistribution of the Products in any form must
 * include this license and copyright notice.
 *
 * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
 * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

#pragma warning disable 0219

#define SPINE_SKELETONMECANIM

using UnityEngine;
using UnityEditor;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Linq;
using System.Reflection;
using System.Globalization;

namespace Spine.Unity.Editor {
    using EventType = UnityEngine.EventType;

    public static class SpineHandles {
        public static Color BoneColor { get { return new Color(0.8f, 0.8f, 0.8f, 0.4f); } }
        public static Color PathColor { get { return new Color(254 / 255f, 127 / 255f, 0); } }
        public static Color TransformContraintColor { get { return new Color(170 / 255f, 226 / 255f, 35 / 255f); } }
        public static Color IkColor { get { return new Color(228 / 255f, 90 / 255f, 43 / 255f); } }
        public static Color PointColor { get { return new Color(1f, 1f, 0f, 1f); } }

        static Vector3[] _boneMeshVerts = { new Vector3(0, 0, 0), new Vector3(0.1f, 0.1f, 0), new Vector3(1, 0, 0), new Vector3(0.1f, -0.1f, 0) };
        static Mesh _boneMesh;
        public static Mesh BoneMesh {
            get {
                if (_boneMesh == null) {
                    _boneMesh = new Mesh { vertices = _boneMeshVerts, uv = new Vector2[4], triangles = new[] { 0, 1, 2, 2, 3, 0 } };
                    _boneMesh.RecalculateBounds();
                    _boneMesh.RecalculateNormals();
                }
                return _boneMesh;
            }
        }

        static Mesh _arrowheadMesh;
        public static Mesh ArrowheadMesh {
            get {
                if (_arrowheadMesh == null) {
                    _arrowheadMesh = new Mesh { vertices = new[] { new Vector3(0, 0), new Vector3(-0.1f, 0.05f), new Vector3(-0.1f, -0.05f) }, uv = new Vector2[3], triangles = new[] { 0, 1, 2 } };
                    _arrowheadMesh.RecalculateBounds();
                    _arrowheadMesh.RecalculateNormals();
                }
                return _arrowheadMesh;
            }
        }

        static Material _boneMaterial;
        static Material BoneMaterial {
            get {
                if (_boneMaterial == null) {
                    _boneMaterial = new Material(Shader.Find("Hidden/Spine/Bones"));
                    _boneMaterial.SetColor("_Color", SpineHandles.BoneColor);
                }

                return _boneMaterial;
            }
        }

        public static Material GetBoneMaterial() {
            BoneMaterial.SetColor("_Color", SpineHandles.BoneColor);
            return BoneMaterial;
        }

        public static Material GetBoneMaterial(Color color) {
            BoneMaterial.SetColor("_Color", color);
            return BoneMaterial;
        }

        static Material _ikMaterial;
        public static Material IKMaterial {
            get {
                if (_ikMaterial == null) {
                    _ikMaterial = new Material(Shader.Find("Hidden/Spine/Bones"));
                    _ikMaterial.SetColor("_Color", SpineHandles.IkColor);
                }
                return _ikMaterial;
            }
        }

        static GUIStyle _boneNameStyle;
        public static GUIStyle BoneNameStyle {
            get {
                if (_boneNameStyle == null) {
                    _boneNameStyle = new GUIStyle(EditorStyles.whiteMiniLabel) { alignment = TextAnchor.MiddleCenter, stretchWidth = true, padding = new RectOffset(0, 0, 0, 0), contentOffset = new Vector2(-5f, 0f) };
                }
                return _boneNameStyle;
            }
        }

        static GUIStyle _pathNameStyle;
        public static GUIStyle PathNameStyle {
            get {
                if (_pathNameStyle == null) {
                    _pathNameStyle = new GUIStyle(SpineHandles.BoneNameStyle);
                    _pathNameStyle.normal.textColor = SpineHandles.PathColor;
                }
                return _pathNameStyle;
            }
        }

        static GUIStyle _pointNameStyle;
        public static GUIStyle PointNameStyle {
            get {
                if (_pointNameStyle == null) {
                    _pointNameStyle = new GUIStyle(SpineHandles.BoneNameStyle);
                    _pointNameStyle.normal.textColor = SpineHandles.PointColor;
                }
                return _pointNameStyle;
            }
        }

        public static void DrawBoneNames(Transform transform, Skeleton skeleton, float positionScale = 1f) {
            GUIStyle style = BoneNameStyle;
            foreach (Bone b in skeleton.Bones) {
                if (!b.Active)
                    continue;
                var pos = new Vector3(b.WorldX * positionScale, b.WorldY * positionScale, 0) + (new Vector3(b.A, b.C) * (b.Data.Length * 0.5f));
                pos = transform.TransformPoint(pos);
                Handles.Label(pos, b.Data.Name, style);
            }
        }

        public static void DrawBones(Transform transform, Skeleton skeleton, float positionScale = 1f) {
            float boneScale = 1.8f; // Draw the root bone largest;
            DrawCrosshairs2D(skeleton.Bones.Items[0].GetWorldPosition(transform), 0.08f, positionScale);

            foreach (Bone b in skeleton.Bones) {
                if (!b.Active)
                    continue;
                DrawBone(transform, b, boneScale, positionScale);
                boneScale = 1f;
            }
        }

        static Vector3[] _boneWireBuffer = new Vector3[5];

        static Vector3[] GetBoneWireBuffer(Matrix4x4 m) {
            for (int i = 0, n = _boneMeshVerts.Length; i < n; i++)
                _boneWireBuffer[i] = m.MultiplyPoint(_boneMeshVerts[i]);

            _boneWireBuffer[4] = _boneWireBuffer[0]; // closed polygon.
            return _boneWireBuffer;
        }

        public static void DrawBoneWireframe(Transform transform, Bone b, Color color, float skeletonRenderScale = 1f) {
            Handles.color = color;
            var pos = new Vector3(b.WorldX * skeletonRenderScale, b.WorldY * skeletonRenderScale, 0);
            float length = b.Data.Length;

            if (length > 0) {
                Quaternion rot = Quaternion.Euler(0, 0, b.WorldRotationX);
                Vector3 scale = Vector3.one * length * b.WorldScaleX * skeletonRenderScale;
                const float my = 1.5f;
                scale.y *= (SpineEditorUtilities.Preferences.handleScale + 1) * 0.5f;
                scale.y = Mathf.Clamp(scale.x, -my * skeletonRenderScale, my * skeletonRenderScale);
                Handles.DrawPolyLine(GetBoneWireBuffer(transform.localToWorldMatrix * Matrix4x4.TRS(pos, rot, scale)));
                var wp = transform.TransformPoint(pos);
                DrawBoneCircle(wp, color, transform.forward, skeletonRenderScale);
            } else {
                var wp = transform.TransformPoint(pos);
                DrawBoneCircle(wp, color, transform.forward, skeletonRenderScale);
            }
        }

        public static void DrawBone(Transform transform, Bone b, float boneScale, float skeletonRenderScale = 1f) {
            var pos = new Vector3(b.WorldX * skeletonRenderScale, b.WorldY * skeletonRenderScale, 0);
            float length = b.Data.Length;
            if (length > 0) {
                Quaternion rot = Quaternion.Euler(0, 0, b.WorldRotationX);
                Vector3 scale = Vector3.one * length * b.WorldScaleX * skeletonRenderScale;
                const float my = 1.5f;
                scale.y *= (SpineEditorUtilities.Preferences.handleScale + 1f) * 0.5f;
                scale.y = Mathf.Clamp(scale.x, -my * skeletonRenderScale, my * skeletonRenderScale);
                SpineHandles.GetBoneMaterial().SetPass(0);
                Graphics.DrawMeshNow(SpineHandles.BoneMesh, transform.localToWorldMatrix * Matrix4x4.TRS(pos, rot, scale));
            } else {
                var wp = transform.TransformPoint(pos);
                DrawBoneCircle(wp, SpineHandles.BoneColor, transform.forward, boneScale * skeletonRenderScale);
            }
        }

        public static void DrawBone(Transform transform, Bone b, float boneScale, Color color, float skeletonRenderScale = 1f) {
            var pos = new Vector3(b.WorldX * skeletonRenderScale, b.WorldY * skeletonRenderScale, 0);
            float length = b.Data.Length;
            if (length > 0) {
                Quaternion rot = Quaternion.Euler(0, 0, b.WorldRotationX);
                Vector3 scale = Vector3.one * length * b.WorldScaleX;
                const float my = 1.5f;
                scale.y *= (SpineEditorUtilities.Preferences.handleScale + 1f) * 0.5f;
                scale.y = Mathf.Clamp(scale.x, -my, my);
                SpineHandles.GetBoneMaterial(color).SetPass(0);
                Graphics.DrawMeshNow(SpineHandles.BoneMesh, transform.localToWorldMatrix * Matrix4x4.TRS(pos, rot, scale));
            } else {
                var wp = transform.TransformPoint(pos);
                DrawBoneCircle(wp, color, transform.forward, boneScale * skeletonRenderScale);
            }
        }

        public static void DrawPaths(Transform transform, Skeleton skeleton) {
            foreach (Slot s in skeleton.DrawOrder) {
                var p = s.Attachment as PathAttachment;
                if (p != null)
                    SpineHandles.DrawPath(s, p, transform, true);
            }
        }

        static float[] pathVertexBuffer;

        public static void DrawPath(Slot s, PathAttachment p, Transform t, bool includeName) {
            int worldVerticesLength = p.WorldVerticesLength;

            if (pathVertexBuffer == null || pathVertexBuffer.Length < worldVerticesLength)
                pathVertexBuffer = new float[worldVerticesLength];

            float[] pv = pathVertexBuffer;
            p.ComputeWorldVertices(s, pv);

            var ocolor = Handles.color;
            Handles.color = SpineHandles.PathColor;

            Matrix4x4 m = t.localToWorldMatrix;
            const int step = 6;
            int n = worldVerticesLength - step;
            Vector3 p0, p1, p2, p3;
            for (int i = 2; i < n; i += step) {
                p0 = m.MultiplyPoint(new Vector3(pv[i], pv[i + 1]));
                p1 = m.MultiplyPoint(new Vector3(pv[i + 2], pv[i + 3]));
                p2 = m.MultiplyPoint(new Vector3(pv[i + 4], pv[i + 5]));
                p3 = m.MultiplyPoint(new Vector3(pv[i + 6], pv[i + 7]));
                DrawCubicBezier(p0, p1, p2, p3);
            }

            n += step;
            if (p.Closed) {
                p0 = m.MultiplyPoint(new Vector3(pv[n - 4], pv[n - 3]));
                p1 = m.MultiplyPoint(new Vector3(pv[n - 2], pv[n - 1]));
                p2 = m.MultiplyPoint(new Vector3(pv[0], pv[1]));
                p3 = m.MultiplyPoint(new Vector3(pv[2], pv[3]));
                DrawCubicBezier(p0, p1, p2, p3);
            }

            const float endCapSize = 0.05f;
            Vector3 firstPoint = m.MultiplyPoint(new Vector3(pv[2], pv[3]));
            SpineHandles.DrawDot(firstPoint, endCapSize);

            //if (!p.Closed) SpineHandles.DrawDot(m.MultiplyPoint(new Vector3(pv[n - 4], pv[n - 3])), endCapSize);
            if (includeName)
                Handles.Label(firstPoint + new Vector3(0, 0.1f), p.Name, PathNameStyle);

            Handles.color = ocolor;
        }

        public static void DrawDot(Vector3 position, float size) {
            Handles.DotHandleCap(0, position, Quaternion.identity, size * HandleUtility.GetHandleSize(position), EventType.Ignore); //Handles.DotCap(0, position, Quaternion.identity, size * HandleUtility.GetHandleSize(position));
        }

        public static void DrawBoundingBoxes(Transform transform, Skeleton skeleton) {
            foreach (var slot in skeleton.Slots) {
                var bba = slot.Attachment as BoundingBoxAttachment;
                if (bba != null)
                    SpineHandles.DrawBoundingBox(slot, bba, transform);
            }
        }

        public static void DrawBoundingBox(Slot slot, BoundingBoxAttachment box, Transform t) {
            if (box.Vertices.Length <= 2)
                return; // Handle cases where user creates a BoundingBoxAttachment but doesn't actually define it.

            var worldVerts = new float[box.WorldVerticesLength];
            box.ComputeWorldVertices(slot, worldVerts);

            Handles.color = Color.green;
            Vector3 lastVert = Vector3.zero;
            Vector3 vert = Vector3.zero;
            Vector3 firstVert = t.TransformPoint(new Vector3(worldVerts[0], worldVerts[1], 0));
            for (int i = 0; i < worldVerts.Length; i += 2) {
                vert.x = worldVerts[i];
                vert.y = worldVerts[i + 1];
                vert.z = 0;

                vert = t.TransformPoint(vert);

                if (i > 0)
                    Handles.DrawLine(lastVert, vert);

                lastVert = vert;
            }

            Handles.DrawLine(lastVert, firstVert);
        }

        public static void DrawPointAttachment(Bone bone, PointAttachment pointAttachment, Transform skeletonTransform) {
            if (bone == null)
                return;
            if (pointAttachment == null)
                return;

            Vector2 localPos;
            pointAttachment.ComputeWorldPosition(bone, out localPos.x, out localPos.y);
            float localRotation = pointAttachment.ComputeWorldRotation(bone);
            Matrix4x4 m = Matrix4x4.TRS(localPos, Quaternion.Euler(0, 0, localRotation), Vector3.one) * Matrix4x4.TRS(Vector3.right * 0.25f, Quaternion.identity, Vector3.one);

            DrawBoneCircle(skeletonTransform.TransformPoint(localPos), SpineHandles.PointColor, Vector3.back, 1.3f);
            DrawArrowhead(skeletonTransform.localToWorldMatrix * m);
        }

        public static void DrawConstraints(Transform transform, Skeleton skeleton, float skeletonRenderScale = 1f) {
            Vector3 targetPos;
            Vector3 pos;
            bool active;
            Color handleColor;
            const float Thickness = 4f;
            Vector3 normal = transform.forward;

            // Transform Constraints
            handleColor = SpineHandles.TransformContraintColor;
            foreach (var tc in skeleton.TransformConstraints) {
                var targetBone = tc.Target;
                targetPos = targetBone.GetWorldPosition(transform, skeletonRenderScale);

                if (tc.TranslateMix > 0) {
                    if (tc.TranslateMix != 1f) {
                        Handles.color = handleColor;
                        foreach (var b in tc.Bones) {
                            pos = b.GetWorldPosition(transform, skeletonRenderScale);
                            Handles.DrawDottedLine(targetPos, pos, Thickness);
                        }
                    }
                    SpineHandles.DrawBoneCircle(targetPos, handleColor, normal, 1.3f * skeletonRenderScale);
                    Handles.color = handleColor;
                    SpineHandles.DrawCrosshairs(targetPos, 0.2f, targetBone.A, targetBone.B, targetBone.C, targetBone.D, transform, skeletonRenderScale);
                }
            }

            // IK Constraints
            handleColor = SpineHandles.IkColor;
            foreach (var ikc in skeleton.IkConstraints) {
                Bone targetBone = ikc.Target;
                targetPos = targetBone.GetWorldPosition(transform, skeletonRenderScale);
                var bones = ikc.Bones;
                active = ikc.Mix > 0;
                if (active) {
                    pos = bones.Items[0].GetWorldPosition(transform, skeletonRenderScale);
                    switch (bones.Count) {
                        case 1: {
                            Handles.color = handleColor;
                            Handles.DrawLine(targetPos, pos);
                            SpineHandles.DrawBoneCircle(targetPos, handleColor, normal);
                            var m = bones.Items[0].GetMatrix4x4();
                            m.m03 = targetBone.WorldX * skeletonRenderScale;
                            m.m13 = targetBone.WorldY * skeletonRenderScale;
                            SpineHandles.DrawArrowhead(transform.localToWorldMatrix * m);
                            break;
                        }
                        case 2: {
                            Bone childBone = bones.Items[1];
                            Vector3 child = childBone.GetWorldPosition(transform, skeletonRenderScale);
                            Handles.color = handleColor;
                            Handles.DrawLine(child, pos);
                            Handles.DrawLine(targetPos, child);
                            SpineHandles.DrawBoneCircle(pos, handleColor, normal, 0.5f);
                            SpineHandles.DrawBoneCircle(child, handleColor, normal, 0.5f);
                            SpineHandles.DrawBoneCircle(targetPos, handleColor, normal);
                            var m = childBone.GetMatrix4x4();
                            m.m03 = targetBone.WorldX * skeletonRenderScale;
                            m.m13 = targetBone.WorldY * skeletonRenderScale;
                            SpineHandles.DrawArrowhead(transform.localToWorldMatrix * m);
                            break;
                        }
                    }
                }
                //Handles.Label(targetPos, ikc.Data.Name, SpineHandles.BoneNameStyle);
            }

            // Path Constraints
            handleColor = SpineHandles.PathColor;
            foreach (var pc in skeleton.PathConstraints) {
                active = pc.TranslateMix > 0;
                if (active)
                    foreach (var b in pc.Bones)
                        SpineHandles.DrawBoneCircle(b.GetWorldPosition(transform, skeletonRenderScale), handleColor, normal, 1f * skeletonRenderScale);
            }
        }

        static void DrawCrosshairs2D(Vector3 position, float scale, float skeletonRenderScale = 1f) {
            scale *= SpineEditorUtilities.Preferences.handleScale * skeletonRenderScale;
            Handles.DrawLine(position + new Vector3(-scale, 0), position + new Vector3(scale, 0));
            Handles.DrawLine(position + new Vector3(0, -scale), position + new Vector3(0, scale));
        }

        static void DrawCrosshairs(Vector3 position, float scale, float a, float b, float c, float d, Transform transform, float skeletonRenderScale = 1f) {
            scale *= SpineEditorUtilities.Preferences.handleScale * skeletonRenderScale;

            var xOffset = (Vector3)(new Vector2(a, c).normalized * scale);
            var yOffset = (Vector3)(new Vector2(b, d).normalized * scale);
            xOffset = transform.TransformDirection(xOffset);
            yOffset = transform.TransformDirection(yOffset);

            Handles.DrawLine(position + xOffset, position - xOffset);
            Handles.DrawLine(position + yOffset, position - yOffset);
        }

        static void DrawArrowhead2D(Vector3 pos, float localRotation, float scale = 1f) {
            scale *= SpineEditorUtilities.Preferences.handleScale;

            SpineHandles.IKMaterial.SetPass(0);
            Graphics.DrawMeshNow(SpineHandles.ArrowheadMesh, Matrix4x4.TRS(pos, Quaternion.Euler(0, 0, localRotation), new Vector3(scale, scale, scale)));
        }

        static void DrawArrowhead(Vector3 pos, Quaternion worldQuaternion) {
            Graphics.DrawMeshNow(SpineHandles.ArrowheadMesh, pos, worldQuaternion, 0);
        }

        static void DrawArrowhead(Matrix4x4 m) {
            float s = SpineEditorUtilities.Preferences.handleScale;
            m.m00 *= s;
            m.m01 *= s;
            m.m02 *= s;
            m.m10 *= s;
            m.m11 *= s;
            m.m12 *= s;
            m.m20 *= s;
            m.m21 *= s;
            m.m22 *= s;

            SpineHandles.IKMaterial.SetPass(0);
            Graphics.DrawMeshNow(SpineHandles.ArrowheadMesh, m);
        }

        static void DrawBoneCircle(Vector3 pos, Color outlineColor, Vector3 normal, float scale = 1f) {
            scale *= SpineEditorUtilities.Preferences.handleScale;

            Color o = Handles.color;
            Handles.color = outlineColor;
            float firstScale = 0.08f * scale;
            Handles.DrawSolidDisc(pos, normal, firstScale);
            const float Thickness = 0.03f;
            float secondScale = firstScale - (Thickness * SpineEditorUtilities.Preferences.handleScale * scale);

            if (secondScale > 0f) {
                Handles.color = new Color(0.3f, 0.3f, 0.3f, 0.5f);
                Handles.DrawSolidDisc(pos, normal, secondScale);
            }

            Handles.color = o;
        }

        internal static void DrawCubicBezier(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3) {
            Handles.DrawBezier(p0, p3, p1, p2, Handles.color, Texture2D.whiteTexture, 2f);
            //			const float dotSize = 0.01f;
            //			Quaternion q = Quaternion.identity;
            //			Handles.DotCap(0, p0, q, dotSize);
            //			Handles.DotCap(0, p1, q, dotSize);
            //			Handles.DotCap(0, p2, q, dotSize);
            //			Handles.DotCap(0, p3, q, dotSize);
            //			Handles.DrawLine(p0, p1);
            //			Handles.DrawLine(p3, p2);
        }
    }
}
